9. Quantum Mechanics

Which of the following are allowed values for the angular momentum quantum number (l) when the principal quantum number (n) is 2?

Which set of quantum numbers is not possible for an electron in an atom?

In the third principal energy level (n = 3), how many different values of the angular momentum quantum number l are possible?

For a principal quantum number n = 5, which of the following lists correctly represents all possible values of the angular momentum quantum number l?